Future B Physics Program at KEK

December 2007

Masa YamauchiKEK

Outline

Introduction: KEKB and BelleNext program of quark flavour physicsKEK’s five year roadmapKEKB upgrade plan → Oide’s talkDetector issuesOrganization of new experimental groupSummary

KEKB and Belle

/ KL detector

Central drift chamberHe(50%)+C2H6(50%)

EM calorimeter (CsI(Tl))

Cherenkov detector n=1.015~1.030

Si vertex detector

TOF counter

SC solenoid 1.5T

Belle DetectorBelle Detector

8GeV e

3.5GeV e

Belle CollaborationBelle Collaboration

BINPChiba U.Hanyang U.U. of CincinnatiEwha Women’s U.Fu-Jen U.Giessen U.Gyeongsang Nat’l U.U. of HawaiiHiroshima Tech.HEPHY, ViennaIHEP, ProtovinoIHEP, BeijingINFN, TorinoITEPKanagawa U.KEKKorea U.

Krakow Inst. of Nucl. Phys.Kyoto U.Kyungpook National U.U. of Lausanne

Jozef Stefan Inst.U. of MelbourneNagoya U.Nara Women’s U.National Central U.National United U.National Taiwan U.Nihon Dental CollegeNiigata U.Nova Gorica U.Osaka U.Osaka City U.Panjab U.Peking U.Princeton U.

Illinois U. - RikenSaga U.

USTC Seoul National U.

Shinshu U.Sungkyunkwan U.U. of SydneyTata InstituteToho U.Tohoku U.Tohuku Gakuin U.U. of TokyoTokyo Inst. of Tech.Tokyo Metropolitan U.Tokyo U. of A and T.Toyama Nat’l CollegeU. of TsukubaVPIYonsei U.

Scientific Achievements of B Factories (1)

Observation of CPV in the B meson system

ACP(t) =(BfCP;t) (BfCP;t)

(BfCP;t) (BfCP;t) = Af cosmt Sf sinmt

Af ~ 0Sf = 0.652±0.039±0.020

Consistent with BaBar’s meas.

B0J/KS

B0J/KS

Belle, July 05

Belle, July 05

Achievements of the B Factories

Quantitative confirmation of the KM model

Af ~ 0Sf = 0.652±0.039±0.020

Violation of CP symmetry !

B0J/KS

B0J/KS

Belle, July 05

Belle, July 05

Discovery of CP violation in BB systemDiscovery of CP violation in BB system

Other highlights

SMBelle, 2005

D0-D0 mixing

AFB in BK*ll

X(3872)

Many new resonances

bdtransition

Evidence for B

and more…

Z(4430)

BD*

Another important achievement

Success of KEKB and PEP-II enabled us to design a new ee B factory with much higher Lpeak.

Asymmetric ee collider with L > 1034

What is next with flavour physics?

If new physics at O(1)TeV…– It is natural to assume that the effects are seen in B/D/

decays.– Flavour structure of new physics?– CP violation in new physics?– These studies will be useful to identify mechanism of

SUSY breaking, if NP=SUSY.

Otherwise…– Search for deviations from SM in flavor physics will be

one of the best ways to find new physics.

KEKB upgrade

Asymmetric energy ee collider at ECM=m((4S)) to be realized by upgrading the existing KEKB collider.

Super-high luminosity 21035/cm2/sec 210 9 BB per yr.

210 9 per yr.

Higher beam current,more RF, smaller y* andcrab crossing L = 21035/cm2/sec

Belle with improved rate immunity

http://belle.kek.jp/superb/loi

Physics at upgraded KEKB

New source ofNew source ofCP violationCP violation

New source of New source of flavor mixingflavor mixing

LFV LFV decays decays

SUSY breaking SUSY breaking mechanismmechanism

Precision test Precision test of KM schemeof KM scheme

Super-high statisticsSuper-high statisticsmeasurements:measurements:

SS, sin, sin22WW, etc., etc.

Charm physicsCharm physics New resonances,New resonances, DD00DD00 mixing… mixing…

Precision test of KM scheme

M.PieriniCKM2006

Quark flavor changing processes

Lepton flavor violation

LHC/ILCSUSY mass spectrum

DiagonalOff-diagonal

SUSY flavour physics: mass matrix of squark and slepton will be determined by their direct production at the energy frontier and flavour physics measurements.

Y.Okada, Nov. 2007

Present upperlimits

Measurementsat upgraded KEKB

（ ab-1 ）

Reach of presentB factories

Reach of upgradedKEKB

Dev

iatio

n fr

om S

M

Deviation from SMDeviation from SM

Relevant to baryogenesis?

Relevant to baryogenesis?

New source of CP violation

New source of CP violation

CP asymmetries of penguin dominated B decays

Searches for new sources of quark mixing and CP violation

Search for new CP phases

In general, new physics contains new sources of flavor mixing and CP violation.

In SUSY models, for example, SUSY particles contribute to the bs transition, and their CP phases change CPV observed in BK, ’K etc.

SM SUSY contribution

In general, if SUSY is present, the s-quarkmixing matrix contains complex phases justas in the Kobayashi-Maskawa matrix.

U-KEKB

T.Goto et al., 2007

A possible hint for NP: b→sqq

Smaller than bccs in all of 9 modes

Smaller than bccs in all of 9 modes

Theory : tends to positive shifts

Naïve average of all b s modes

sin2eff = 0.52 ± 0.05 2.6 deviation from SM

Naïve average of all b s modes

sin2eff = 0.52 ± 0.05 2.6 deviation from SM

Search for new flavor mixing

?b quark s quark

l l : Probe the flavor changing

process with the “EW probe”.

Theoretical predictions for ll forward-backward charge asymmetry for SM and SUSY model with various parameter sets.

, Z0

The F/B asymmetry is a consequence of -Z0 interference.

This measurement is especially sensitive to new physics such as SUSY, heavy Higgs and extra dim.

Ratio of branching fractions Branching fraction CP asymmetry q 2 distribution Isospin asymmetry Triple product correlation Forward backward asymmetry Forward backward CP asymmetry

Possible observables:

Precise measurements of decays

LF violating decay?

Integ. Lum. （ ab-1 ）Reach of B factories

Upgraded KEKB

Upper limits

->e

>e

T.Goto et al., 2007

B decays with more than one

10ab-1

Bdecays

tan cotb um m

b

u H/W

tanm

B

Search region withB decays

Provides a unique method to measure b-H±-u andb-H±-c coupling strength.

Provides a unique method to measure b-H±-u andb-H±-c coupling strength.

Interactions of H±

Belle, 2006400fb-1

Υe e

B

B

full reconstruction

0.2~0.3% for B+

D

B decays into invisible particles?

B K(*)or_

Light dark matter can besearched for in the upgradedKEKB.

Light dark matter can besearched for in the upgradedKEKB.

Heavy dark matter is beingsearched for in direct detectionexperiments.

Heavy dark matter is beingsearched for in direct detectionexperiments.Model prediction

Light dark matter?

Search for right handed interaction

CP violation in B KS 0

Pre

cisi

on o

f th

e m

easu

rem

ent

Present exp. precision

Reach of upgradedKEKB SM

Sizable CP asymmetry is expected in B0Xs decay, if right-handed interaction exists in new physics.

Sizable CP asymmetry is expected in B0Xs decay, if right-handed interaction exists in new physics.

Left-right summetry in new physics?

U-KEKB

T.Goto et al., 2007

Identification of SUSY breaking scenario

Bd- unitarity

m(Bs) B->Ks B->Ms indirect CP

b->s direct CP

mSUGRA- - - - - +

SU(5)SUSY GUT + R

(degenerate)

- + + - + -

SU(5)SUSY GUT + R

(non-degenerate)

- - + ++ ++ +

U(2) Flavor symmetry + + + ++ ++ ++

++: Large, +: sizable, -: small

Observ-ables

SUSYmodels

Pattern of deviations from the Standard Model Y.Okada

Strong competitors

Comparison with LHCb

ee is advantageous in… LHCb is advantageous in…

CPV in B→KS, ’KS,…

CPV in B→KS0

B→K, , D(*)

Inclusive b→s, see

→ and other LFV

D0D0 mixing

CPV in B→JKS

Time dependent measurements of BS

Bc and bottomed baryons

Most of B decays not including or

B(s,d)→

These are complementary to each other !!

Roadmap -HEP-

• According to the JAHEP community’s master plan,– Highest priority is given to ILC– Before ILC, promote flavor physics at KEKB and J-PARC

• Action before the ILC approval– ILC R&D– Completion/commissioning of J-PARC

• Considering the world competition, it is urgent to improve neutrino intensity

– Continuation of KEKB/Belle with upgrade

Energy Frontier

ILC R&D Construction Experiment

LHC

Flavor Physics at Luminosity/Intensity Frontier, K, ,... at J-PARC

b, c, ,... with upgraded- KEKB/Belle

2006 2008 2010 2012 2014 2016 2018

KEK Roadmap

KEKBexperiment upgrade experiment

Compact ERLR&D construction experiment

R&D

PFexperiment

Detector R&D

J-PARCconstruction experiment + upgrade

ERL R&D construction experiment

ILCR&D

construction

Preliminary

Belle upgrade

New Dead time free readout and high speed

computing systems

Faster calorimeter with Wave sampling and pure CsI crystal Super particle identifier with

precise Cherenkov device

Si vertex detector withhigh background

tolerance

Background tolerant super small celltracking detector

KL/ detectionwith scintillator

and new generationphoton sensors

Requirements to the detector

- low p identification s recon. eff.- hermeticity “reconstruction”

- radiation damage and occupancy- fake hits and pile-up noise in the EM

- higher rate trigger, DAQ and computing

Issues Higher background ( 20)

Higher event rate ( 10)

Require special features

Possible solution: Replace inner layers of the vertex detector with a silicon striplet detector. Replace inner part of the central tracker with a silicon strip detector. Better particle identification device Replace endcap calorimeter by pure CsI. Faster readout electronics and computing system.

Possible solution: Replace inner layers of the vertex detector with a silicon striplet detector. Replace inner part of the central tracker with a silicon strip detector. Better particle identification device Replace endcap calorimeter by pure CsI. Faster readout electronics and computing system.

MCP-PMT

(TOP)

New experimental group

It will be practical to build a new detector by upgrading the existing Belle.

However, the experimental group will be a new group, not an extension of the present Belle collaboration. Name of the new group will not be Belle or SuperBelle.

New participants are all welcomed and have equal opportunities to work on detector construction and physics.

It is welcomed to join the new group, but not Belle.

Interim Steering Committee is being formed. First meeting is scheduled March 2008, inviting potential new collaborators.

2007 2008 2009 2010

Experiment at KEKB

4 71 10 414 71 104 71 104 71 1010

2011 2012

KEKB/Belle upgrade

DetectorStudy Report(March 08)

Final detectordesign(April 09)

Pre kick-offmeeting(March 08)

2007 2008 20094 71 1 42 1010 3 5 8 9 11 12 2 311 12 6

Detector proposals Internal review

TDR

BNM(January 08)

One-day general meeting and an IB meeting at every BGM

Meeting plan

Actions to invite new collaborators

Kick-offmeeting(July 08)

Summary

KEKB/Belle and PEP-II/BaBar have been running very successfully, and brought important scientific and technical achievements.

Next generation ee B factory with L~1036 will be very useful to study the new sources of flavor mixing and CP violation.– Search for new CPV in bs transition – Very precise test of CKM scheme– Search for lepton flavor violating decays– Studies of H± interactions with fermions– Very precise measurements of S(@10GeV), sin2W(@10GeV)…

KEK Roadmap includes KEKB upgrade. KEKB machine upgrade plan Oide’s talk Detector upgrade necessary to improve BKG/rate immunity. New collaboration to be formed soon.

Barrel PID (TOP)

Quartz: 255cmL x 40cmW x 2cmT

– Focus mirror at 47.8deg. angle() y(); correct chromatic dispersion t()

Multi-anode (GaAsP) MCP-PMT– Linear array (5mm pitch), Good time resolution (<~40ps)

MCP-PMT

lifetime to be checked

re-polishing going on

New resonances

c’ & e+e-ccccD0*0 & D1*0

X(3872)

c* baryon triplet

X(3940), Y(3940)c2’

Y(4660) Y(4008)

DsJ(2700)cx(3090)

Z(4430)

DsJ(2317/2460)

DsJ(2860)

Y(4260)

Y(4320)

New resonances found at Belle

Among them X （ 3872 ） andZ （ 4430 ） are considered to be“exotic” states.

Among them X （ 3872 ） andZ （ 4430 ） are considered to be“exotic” states.

More and more exotic states will beObserved by the upgraded KEKB.

More and more exotic states will beObserved by the upgraded KEKB.

More than 10 new resonanceshave been found at Belle

More than 10 new resonanceshave been found at Belle

Bkg & TRG rate in futureBkg & TRG rate in future

KEKB SuperB

Luminosity(1034cm-2sec-1)

~1.7 ~50

HER curr. (A)

LER curr. (A)vacuum (10-7Pa)

1.2

1.6

~1.5

4.1

9.4

5

Bkg increase - x 20

TRG rate (kHz)phys. origin

Bkg origin

0.40.2

0.2

1410

4Shynchrotoron radiationBeam-gas scattering (inc. intra-beam scattering)Radiative Bhabha

SVD CDC PID / ECL KLM

KEKBBkg

x10 Bkg

x20 Bkg

Endcap PID (A-RICH)

1.0451.050

1.0551.062

Npe = 9.1, (track) = 4.2 mrad achieved

~5.5separation for 4 GeV/c K/

“Focusing” Aerogel radiator

Photon Sensors– Sensitive to single photon

• High QE >~ 20 %• High gain

– Position detection accuracy: ~5x5 mm2

– Large effective area: >~ 70 %– Operational with 1.5 Tesla magnetic field

Hybrid (Avalanche) Photon DetectorMCP (Micro Channel Plate) PMTSi-PM/MPPC